Can we make sure we make the most of the promising ideas people come up with to restrain and adapt to the changes we’re making to the climate? I’ve been considering this question thanks to a recent invention seeking to help cut increasing greenhouse gas emissions that arise from feeding the world’s growing population. Stuart Licht’s team at George Washington University in Washington, DC, has worked out how to make a key component of fertiliser – ammonia – that could eliminate emissions and minimise cost. In fact it’s an extension of a method that Stuart told me can also produce zero carbon cement, iron, bleach, magnesium, and capture CO2 directly from the atmosphere. So when will we see this amazing approach in use? I can’t tell you that – because Stuart has no plans to commercialise it.

I became aware of the new ammonia production system when Chemistry World asked me to cover it for them. Ammonia is a simple molecule, comprising only two elements, hydrogen and nitrogen. Humans have been using it in fertiliser since at least the early 19th century, when it was mined, both in mineral form and as bird guano, for delivery to farmers. That was necessary because although nitrogen is hugely abundant – it makes up four-fifths of Earth’s atmosphere – it’s equally as unreactive. Chemists often replace the air above the reactions in their flasks with pure nitrogen when they’re worried that oxygen will affect their results. That stability meant synthetic ammonia was at first elusive.

But in the early 20th century Fritz Haber and Carl Bosch found a way to overcome nitrogen’s reluctance to react. They could take nitrogen from the air, and bring it together with hydrogen gas in the presence of an osmium catalyst at very high pressures and temperatures. During the First World War ammonia’s other main application – as a basis for explosives – saw that ramped up to industrial scale. The Haber-Bosch process has provided fertilisers that have been crucial in feeding Earth’s growing population since then. But it comes with a downside: it requires huge amounts of energy – 2% of the entire world’s consumption – whose generation usually releases the greenhouse gas CO2. Read the rest of this entry »

Uncertainty cuts both ways highlights University of Bristol’s Stephan Lewandowsky – if your preferred estimate is at the low end of a range, you’re neglecting similarly likely high end estimates. Image credit: University of Bristol

These messages could hardly be any clearer, but still some of us remain uncertain on the need to act. The best argument for waiting until we’re more certain to act is that if climate change turns out to be harmless, our efforts to fight it will be wasted. Even simple things like current weather are enough to sway our opinions, and when uncertain it’s always tempting to feel like we don’t need to do anything. But that’s the wrong reaction to uncertainty on climate change, according to psychologist Stephan Lewandowsky from the University of Bristol, UK.

A measurement taken on a shaded back deck in Oswego, Oregon on July 29, 2009 at 6pm. 41.3°C or 106.34°F – just one example of increasingly common hot summers in the Northern Hemisphere. Image copyright Sean Dreilinger used via Flickr Creative Commons licence.

Human influence on climate is set to make otherwise unusually hot summers in the Northern Hemisphere more frequent, even if the current warming slowdown continues. That finding, from a new study by Youichi Kamae from the National Institute for Environmental Studies in Tsukuba, Japan, and his colleagues, could now heat up climate talks. “The recent hot summers over land regions and the climate hiatus have opposite effects on ongoing global negotiations for climate policies,” Youichi underlined. “The findings of this study can have significant implications for policy makers.”

Over the past 15 years, growing ‘anthropogenic’ or human-emitted CO2 hasn’t turned into significant average temperature rises on the Earth’s surface. The top levels of the oceans haven’t warmed significantly either, even though heat is still building up deeper down. However in that time sometimes deadly hot summers have become more common in Earth’s northern half. It’s not clear how that’s happening without average temperatures increasing faster. One possible part of the explanation could be a fast response to greenhouse gas emissions that Youichi and other scientists had previously found. “The fast response over can largely be interpreted as direct land surface warming due to CO2,” Youichi told me.

UK Prime Minister David Cameron visiting Dawlish a week after the storms that demolished the sea wall that supported the train line. Image copyright Number 10, used via Flickr Creative Commons license.

Taking the train along the Devon, UK, coast earlier this week I was hypnotised by the lapping waves I saw through the window, and their concealed power. On such a sunny day, the rail journey through Dawlish is perhaps the most beautiful I’ve been on. But in February its ocean-hugging route became its downfall, when storms demolished the sea wall it rests on. Now, thanks to 300 fluorescent-jacket clad workers who performed £35 million worth of repairs, the dangling tracks I saw on TV news are a fading memory. It’s an impressive achievement, but could we afford it if – due to climate change, for example – such ‘orange armies’ had to do battle more often?

The significance of that question was emphasised by Chris Field from Stanford University in California, when I saw him talk recently. Highlighting that all parts of the world are vulnerable to climate change, Chris showed the below image of New York City in 2011, during Hurricane Sandy. “The existing climate created a situation that caused over $50 billion in economic damage for a region of the world that had a vast amount of economic resources and had a response plan in place,” he underlined. “It just wasn’t a plan that was up to the challenges that they faced.” If climate change causes more $50 billion-damage events, can we afford that?

If New York can be taken unaware by Hurricane Sandy, what happens elsewhere, when sea level’s higher? Image credit: Chris Field/IPCC

Just before the ocean crippled the south-west UK’s rail services, Jochen Hinkel from the Global Climate Forum in Berlin, Germany, and his team were answering a similar question. In a paper published in the Proceedings of the National Academy of Sciences of the USA in February, Jochen looked at coastal flood damages from projected sea level rise. When I therefore asked him about his work, he was quick to put climate change-driven sea level rise’s role in Hurricane Sandy and this year’s UK storms into context. Read the rest of this entry »

A Roman altar with the Sun in its chariot on the left, and Vulcan, the god of fire and volcanoes on the right. The climate gods long favoured the Roman Empire, with Earth’s orbital dance credited for increasing the amount of solar energy falling on Earth at the time. Image copyright: Nick Thompson, used via Flickr Creative Commons License.

Our climate has changed before. It’s something most of us realise and can agree on and, according to Skeptical Science, it’s currently the most used argument against human-caused warming. If such changes have happened naturally before, the argument goes, then surely today’s warming must also be natural. It’s an appealing idea, with an instinctively ‘right’ feel. Nature is so huge compared to us puny humans, how can we alter its course? The warming we’re measuring today must just be a natural fluctuation.

It’s such an appealing argument that at the beginning of the 20th century that’s just what many scientists thought – that humans couldn’t alter Earth’s climate. In the time since, our knowledge has come a long way. We’ve explored space, become able to build the electronics that are letting you read this, and climate science has likewise advanced and benefited from these advances.

So what do we know today that might convince the sceptical scientists of 115 years ago that we’re warming the planet? Recently, Richard Mallett, one of my Twitter friends who describes himself as sceptical about mainstream climate science, made a point that serves as an excellent test of our current knowledge:

@andyextance Climate science should be able to explain the Holocene, Roman, Medieval and current warmings and the cold periods in between.

Of the historical warmings he’s referring to, perhaps the least familiar is the Holocene, which is ironic, as the Holocene is now. It’s the current period of geological time that started at the end of the last ice age, 11,700 years ago. By 1900 scientists would have known the term, but they couldn’t explain why it wasn’t as icey as before.

Three variables of the Earth’s orbit—eccentricity, obliquity, and precession—affect global climate. Changes in eccentricity (the amount the orbit diverges from a perfect circle) vary the distance of Earth from the Sun. Changes in obliquity (tilt of Earth’s axis) vary the strength of the seasons. Precession (wobble in Earth’s axis) varies the timing of the seasons. For more complete descriptions, read Milutin Milankovitch: Orbital Variations. Image credit: NASA/Robert Simmon.

The explanation we have today comes thanks to the calculations Milutin Milanković worked out by hand between 1909 and 1941. Milutin showed that thanks to the gravitational pull of the Moon, Jupiter and Saturn, Earth’s orbit around the Sun varies in three ways. Over a cycle of roughly 96,000 years our path varies between more circular and more oval shapes. The other two ways come because Earth’s poles are slightly tilted relative to the Sun’s axis, which is why we have seasons. The angle of that tilt shifts over a roughly 41,000 year cycle. Earth also revolves around that tilted axis, like a spinning top does when it slows down, every 23,000 years.

Between 1970 and 2010 the average weight across all overweight and obese American men and women increased approximately 5 kg and 6 kg, respectively, and that has added to the fuel needed to transport them, and greenhouse gas emissions in turn. Image copyright Neil Hester, used unaltered via Flickr Creative Commons license.

In case we needed any reasons other than health to watch our weight, a team at Carnegie Mellon University in Pittsburgh, Pennsylvania, has found some. Michelle Tom and her co-workers have looked at how our extra weight adds to the cost and carbon footprint of transport in the US. From 1970 to 2010, the extra fuel needed to carry overweight passengers’ ‘excess weight’ cost $103 billion in total. That in turn created extra greenhouse gas emissions over the 40-year period equivalent to half a billion tonnes of CO2. “Obesity is not just a public health issue, but also has implications for natural resource use and environmental degradation,” Michelle told me.

Weight is important in vehicle fuel use, with developing lighter cars playing a key role in recent efforts to make them more efficient. Working with PhD supervisor Chris Hendrickson, Michelle is studying the strain our heavier societies put on our resources, and therefore tackled the fuel burden from extra weight. “There have been headlines about the health issues associated with people being overweight and obese, but there has been very little analysis of what this means in terms of things like fuel use and calorie intake,” Chris noted.

Michelle pulled together data for personal vehicles, public transport and aircraft, including how many there are, how full they are, and how much fuel they’ve used. And thanks to efforts made to lighten vehicles, she also had access to good information on how weight affects fuel consumption. She could bring this together with records of the US population, how many of them drive, and how much they exceed the highest ‘normal’ body mass index. Combining all this with data on vehicle greenhouse gas emissions and fuel costs meant Michelle could calculate how heavy the impact of heavier people has been. Read the rest of this entry »

Fewer steel beams and using buildings for their whole design life could cut construction emissions by up to 80% suggest the University of Cambridge’s Muiris Moynihan and Julian Allwood. Image copyright Mark Kirchner, used via Flickr Creative Commons licence.

UK engineers have found a way to bulldoze the building industry’s emissions of the greenhouse gas CO2. The University of Cambridge’s Muiris Moynihan and Julian Allwood say that better use of steel could halve emissions without any impact on safety. ‘We’re using double the amount of steel that we actually need,’ Julian told me.

Julian is director of UK Indemand, one of six national centres the country’s government set up in 2013 to help reduce energy demand by boosting efficiency. Construction is one of the first areas it’s tackling in its mission to reduce industrial energy and material use, and in turn cut CO2 emissions.

Today builders use lots of steel because ‘the cost of materials is low, and the cost of structural engineers is high’ Julian said. “Rather than designing a building precisely it’s cheaper to focus on the heavily loaded areas of the building and design carefully there. Then you can copy and paste, in effect, that design out to other areas that are less well loaded because you know it’s going to be safe. It’s quicker to do that than to spend the professional time required to design the structure accurately.”

Steel-making has one of the largest carbon footprints of any industry, its factories coming fourth in the list of ‘stationary emitters’ behind electricity generation, cement production and oil refining. Every year over 1.5 billion tonnes of steel are produced, emitting around one-tenth of the CO2 from energy generation and industrial processes worldwide. Julian and his coworkers had previously forecast that steel use will double in the next 37 years. If reducing steel use is possible, it therefore looks an obvious move to help avoid dangerous climate change. Read the rest of this entry »